title: Second virial coefficients of dipolar hard spheres.
abstract: An asymptotic formula is reported for the second virial coefficient B(2) of a dipolar hard-sphere (DHS) fluid, in zero external field, for strongly coupled dipolar interactions. This simple formula, together with the one for the weak-coupling B(2), provides an accurate prediction of the second virial coefficient for a wide range of dipole moments, including those that are experimentally accessible in magnetite ferrofluids. The weak-coupling B(2) also yields an estimate of the magnetic moment minimally needed for isotropic gas-liquid phase-separation, if any, in the DHS fluid.
authors.affiliation: Van't Hoff Laboratory for Physical and Colloid Chemistry, Utrecht University, Debye Institute for Nanomaterials Science, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Albert P
authors.initials: AP
authors.lastname: Philipse
authors.forename: Bonny W M
authors.initials: BW
authors.lastname: Kuipers